(CNN) - CNN projects Mitt Romney will win all three of Tuesday's Republican presidential primaries, including Wisconsin, where the loss for Rick Santorum may damage his ability to convince Republicans that he can stop Romney from getting the nomination.

Romney's wins in Wisconsin, Maryland and the District of Columbia will put him past the halfway mark to the 1,144 delegates needed to clinch the nomination and add to a wide delegate lead that he holds over the other major GOP presidential candidates, according to CNN estimates.